The proposed invention is a device (100) for fracturing a geological reservoir of hydrocarbons which comprises two sealing liners (102, 103) together defining a confined space (104) in a well drilled into the reservoir, an apparatus for regulating the temperature of a fluid in the confined space, a pair of two electrodes (106) arranged in the confined space, and an electric circuit for generating an electric arc between the two electrodes. The circuit comprises at least one source of voltage linked to the electrodes (106) and an inductance coil between the voltage source and one of the two electrodes. The invention therefore allows the improved fracturing of the reservoir.